Method of forming axle housings



Nov. 21, 1944. w. J. s. EKlNs METHOD 0F FORMING AXLE HOUSINGS Filed April 27, 1942- 4 Sheets-Sheet 1 fmfeww WILLIAM :JACK STEPHEN Elf/NS Nov'. 21, 1944. w.-J. s. EKlNs METHOD oF FORMING AXLE HoUsINGs Filed April 27, 1942 Nov. 21, 1944. w. J. s. EKxNs METHOD 0F FORMING AXLE HOUSINGS Filed April 27, 1942 4 Sheets-.Sheet 4 Patented Nov. 21, 1944 vkrisica ,METHOD oF FORMING AXLE noUsINGs William Jack stephen Enns, Buchanan, Mich.,

assigner to Clark Equipment Company,

Buchanan, Mich., a corporation of Michigan Application April 27, 1942, Serial No. 440,726

6 claims. (o1. zii-153.1)

This invention relates to a method of forming axle housings, and more particularly is concerned with the formation of an axle housing of the banjo type in which the banjo frame for supporting the ldifferential carrier is oiset with respect" tothe longitudinal center of the housing.

Such housings are employed in connection with tion a throat forming machine similar to that u shown in Spatta Patent No. 1,912,600, issued June 6, 1933, is provided for carrying out the method proposed,- which includes the use of a ram to which "is detachably secured a mandrel which enters into the banjo portion of the housing and trucks and other automotive equipment where more than one driving axle is required, since it is obvious that the drive shaft from the transfer case of the vehicle must be laterally oiset to reach the various housings containing the driving axles, and consequently the banjo frame which supports the diierential mechanism in theV culty; However, when the banjo portion is offset,

the tapered vthroat which leads from the banjo to the arm of the housing extends through the section Where the spring pad must be applied. Several schemes have been developed for apply- Y ing a spring pad to this throat portion, such as disclosed lin the patent to George Spatta, No. 2,273,336, issued February 17, 1942,in which the throat is cut or slotted and the spring pad is then set into position and welded. There are some disadvantages of such a construction, however, in""addition to the increased cost of the separate operations of cutting out an arcuate slot and then Welding a special type of spring pad in position thereon.

The present invention overcomes these diliculties by providing a novel method of forming such housings, which includes the step of forming a depression in the throat of the housing during the swaging operation in which the throat is straightened and formed to accurate size. This depression is produced by the use of an anguupon opposite movement of the ram, swages the throat into a corresponding female die to move the metal of the throat into proper-position for forming a smoothly tapered throat leading from a semicircular adjacent portion of the cylindrical banjo. In forming the particular axle housing desired in the present invention, the ram is adapted to receive alternately a standard mandrel'for that side' of the throat which connects to the longer arm of the housing and a special' mandrel when the opposite throat is vto be formed, which special mandrel is so shaped that after the throat has been swaged into position,

larly disposed plunger cooperating with the` throat forming machine, and selectively operable to force the metal at that portion of the throat where the spring pad is to be located inwardly to provide a horizontal flatted portion in the throat upon which the spring pad can be mounted while maintaining the other metal in the throat against deformation in any direction.

Preferably,`in .a preferred form of the inventhe seat forming plunger can operate in conjunction with the mandrel to depress the metal in the throat on the upper side thereoi` to provide the horizontal seat for the spring pad.

The `present invention contemplates, in carrying out the present method, an automatic electrically controlled system controlling the delivery of pressure to various operating cylinders which control the operation of the plunger and the ram. This system is so arranged that upon alternate operations of the ram, the plungerwill be actuated whereby the spring pad will be formed in one throat forming operation but not in the other throat forming operation. y

With the present-method, it is possible to form i such throats in the housing with a minimum of time and with no appreciable additional expense of operation. The mechanism is fully automatic in operation, although obviously it could be manually controlled if desired, and constitutes a considerable advance in the art of forming rear axle housings of the oiset type.

Other objects and advantages of the present invention will appear more fully from the following detailed description which, taken in conjunction with the accompanying drawings, will disclose to those skilled in the art, the particular construction and operation of a preferred form of the present invention.

In the drawings: Figure 1 is a schematic showing of the pres sure and electric control system utilized in performing this operation upon the axle housing;

Figure 2 is an elevational view of the mechanism which is operated to form the spring pad .Seat in the throat of the banjo;

Figure 3 is a sectional view taken substantially on line 3-3 of Figure 2;

Figure 4 is a sectional view taken substantially on line 4-4 of Figure 2;

Figure 5 is an elevational view of a housing May 8, 1934. It win be noted that this axlek housing, indicated generally at 5, is provided with a cylindrical banjo portion 6 and with tapering throat portions 1 connecting the banjo to the oppositely extending arms 8. tions 1 of such a housing, due to the banjo forming operation, are provided with humps or ir regularities 9 which normally are removed by means of the throat forming equipment shown in Spatta Patent No. 1,912,600 of June 6, 1933.

In forming the throat, there is normally employed a ram, such as indicated at I0 in Figure 1, connected for operation by a piston operating in cylinder I2. At its end the ram is provided with means for locking a mandrel, such as the mandrel I3, thereto. This mandrel operates in a suitable female `die block, indicated generally at I4, and having a banjo receiving die `portion I5 for receiving the adjacent, half of the cylindrical banjo frame, and a throat receiving portion I6 for receiving the throat of the housing. The mandrel I3, when connected to the ram IIJ, produces a uniformly tapered throat leading from the semi-cylindrical banjo section to the arm of the housing. For purposes of the present invention, however, there is provided a secondv mandrel I1 which, as shown in detail -in Figure 2, is provided with a iiatted portionl I8 and a rather abruptly rising surface I8 which then The throat por-` merges into the generally -arcuate shape of the l cylindrical banjo frame. The die block I4 in this form of the invention is provided with an offset exten-sion 20 carrying a siritable frame 22 upon which is supported the cylinder 23 which operates the spring pad seat forming plunger. The cylinder 23 carries a suitable piston having the extension 24 projecting into the frame 22, and provided with a cross head 25 operating in the web or partition 26 of the frame supporting the piston against lateral flexing. At the end of the cross head 25 there is provided the ring 26 connected to the connecting point of the links 21 and 28 which provide a toggle joint, the o pposite end of the link 21 being connected to the plunger 29 reciprocatory within a suitable recess in the extension 211. 'I'he link 28 at its opposite end is fulcrumed on the pin 30 supported on the bracket 32 secured by means of the nut 33 to the frame 22. The bracket. 32 is adjustable in position by means of the adjusting screws 34. A suitable' stop screw 35 is provided carried by the end wall 36 of the frame for preventing the toggle joint pin 31 from passing over center.

In Figure 2 the mechanism isl shown in its fully operated position with the plunger 29 fully projected into the recess 38 in the extension 20, and thereby pressing against the outer surface -of the housing wall 39 to press it into position against the mandrel I"1, thereby forming the spring -seat portion 48 shown in Figure '7. At its lower end the plunger 29 is provided with a die member 42 which is shaped to provide the desired cooperation with the mandrel I1 for producing the latted spring seat. The lower end of this die member 42 is indicated at 43 in Figure 3, and when the plunger is retracted in position by the piston rod 24 moving the toggle joint away from the stop 35, the lower end 43 of the die 42 is moved upwardly an amount sufcient to clear the transverse channel 44 formed in the die block I4. This allows the auxiliary die member 45 to be moved laterally into position over the opening 46 in which the mandrel I1 is disposed, the auxiliary die 46 having the arcuate shaped die surface 41 which cooperates with the standard mandrel I3 to form a full throat on the oppoiste side of the housing. The movement of the auxiliary die 45 laterally is controlled by a rod 48 operating within a pressure cylinder 49 secured by means of the bracket 58 to the side of the die block I4. The cylinder 49 is also alternately controlled so that as the plunger 29 is retracted in position and the opposite end of the housing inserted in the die block I4, the auxiliary die 45 will be moved into position to provide the standard throat shape.

In Figure 4 there is disclosed the details of the cross head construction for the piston rod 25 which operates the spring seat forming the plunger 29. The partition wall- 26 of the frame 22 is provided with the transverse substantially cylindrical opening 50, and the cross head 25 connecting the piston rod 24 to the link 26 is provided with arcuate shoes 52 forming suitable slides for guiding the cross head in the intermediate partition 26.

It will be noted that the auxiliary frame carrying the plunger operating mechanism and incated'at 22 is supported on the die block I4 by means of inturned ange portions 53 carried at the lower end of the frame and sliding in suitable ways v54,'whereby the frame can be adjustedl longitudinally with respect to the die block I4. Suitable locking screws 55 serve to lock the frame in desired position. l

Considering now Figure 1 of the drawings which discloses a schematic pressure and electrical control system for the automatic operation of this mechanism, there is provideda spool 60 having arms 62, V`63 and 64 thereon adapted to be engaged by the actuating b'ar'65 carried by the ram or plunger I8 controlled through cylinder I2. The cylinders I2 and 23 have pressure supplied thereto from an oil pump indicated at 68, which has its pressure side 61 connected through conduits 68 and 69 to suitable solenoid control valves 18 and 12, respectively. Ihe solenoid control valve 10 has outlet conduits12 and 13 leading to opposite ends of the cylinders 23 for effecting selected reciprocation of piston rod 24. The valve 1.2 has conduits 14, and 15 connected to opposite ends of the cylinder I2 for selectively reciprocating the ram or plunger I0. The return lines from the valves 1I) and 12 to the'pump are indicated by the dotted line conduit 16.

In the operation of this mechanism, the mandrel I3 is rst placed upon the end of the ram I0, and the housing is placed in position for a standard throating operation in the die block I4. The main starting switch 11 is ,then actuated which actuates the valve 12 to admit Huid under pressure from conduit 69 through conduit 14 to the forward end of cylinder I2, thereby retracting throat of the housing to perform the standard throat forming operation. At this time, the cylinder 49, which is supplied with pressure from a control valve 18 receiving pressure from the supply conduit 1.9 has the switch 88 of the electrically controlled actuator, for the valve 18 closed, whereby the valve is open to allowpressure from the supply line 19 to pass through the valve and conduit 82 to the right' hand side of cylinder 49, as viewed in Figure 1, whereby the profile die 45 carried by the piston arm 48 is moved into position within the die block It in the transverse channel M. At this time, lthe plunger 29 is in retracted position. As a result, when the mandrel i1 is forced into the throat of the housing, a uniform symmetrical throat is formed in this end of the banjo.

When this throating operation is nished, theI stop button of the starting switch 11 is actuated, which in turn controls thevalve 'I2 to admit pressure from conduit 69 through conduit 15 to cylinder i2, thereby releasing the ram i8 for movement to unloading position. At the same time, as the ram l@ moves to the left, the arm 85 4thereof rotates the spool 60, but since the arm 63 is shorter than either arm 62 or 64, the switch 80 remains closed, and consequently the proflle die 45 remains in position. The housing is then reversed with the short en d placed in the die block and with the same mandrel I3 on the ram I8. VThe starting switch at 11 is re-engaged, whereby the same cycle of operation is reproduced in the opposite throat of theV housing, thereby providing a lsmooth throat in more or less conventional manner for both throats of the housing. Upon pressing the stop button of the switch 11, the ram moves to the left to unloading position, and in this case the arm 62 is rotated into position, closing switch 83, while arm 64 opens switch 80. As a result of this operation, the cylinder 49 receives pressure from control valve 18 through conduit 82, withdrawing the pronle die 45 from the recess 44,' and thereby clearing the way for operation of plunger 29. When the prole die 45 moves outwardly of the recess 44, the bracket 85 carried at the end ofv this die operates to close a circuit from the pressure switch 86 in conduit line 14 through the conductor 81 and switch 88, thereby establishing a circuit through conductor 89 to the solenoid control 90 at the left hand side of control valve 10. This circuit is not completed but ismerely conditioned for operation, land completion of the circuit is dependent upon operation of the pressure switch 86. The mandrel I1 is then placed upon the ram- I0 and the start switch'at 1.1 is again engaged.

This results in the ram being drawn through the housing arm moving the mandrel I1 intov position in the throad of the housing. As the mandrel moves into position, the pressure in conduit 14 increases to a point where pressure switch 88 closes, thereby establishing a circuit to the solenoid actuator 90. This in turn opens the valve 10 to allow fluid under pressure to flow from conduit B8 through conduit 12 to the outer end of cylinder 23. This forces the piston rod '24 outwardly of the cylinder straightening the joint has reached limiting position as provided by the stop screw. 35, the pressure in conduit 12 builds up to a point to which it operates the pressure switch SI, closing the circuit from conductor 92 to conductor 93, thereby energizing the.

solenoid actuator 94 at the opposite side of the valve 10. This in turn allows the pressure in the left 'hand end of cylinder 23 to be exhausted through conduit 12 and return line 16 while pressure builds up in the opposite end of the cylinder through conduit 13, thereby retracting plunger 29 outwardly through recess 38. The stop switch is then energized at 11, unloading the ram andthe housing to provide the desired spring spacing beneath the vehicle.

It is' not believed necessary `to go into all the details of the construction and operation of the various valves and control mechanisms associated with the present invention, as they form no part of the method of forming such housings by the present invention. Sufice it to say that with this type of control system, the housing has its throat swaged to proper shape, and the spring pad seat formed therein automatically.

It is to be understood that other means and methods of control might be employed without in any way departing from the scope and spirit of the present invention, and I therefore do not intend to be limited except `as deiined by the scope and spirit of the appended claims.

I claim:

l. In the method of forming a rear axle housing of the offset banjo type, which includes forming a cylindrical banjo section having oppositely extending arms of unequal length, inserting a mandrel in the throat between said banjo section and each arm to formsmoothly tapering throat portions by drawing said mandrel and housing into a die, and inserting a second mandrel having a relieved portion into one of said throat portions and forcing said` mandrel and housing again into said die, the novel step of forming a horizontal spring pad seat which comprises forcing metal in said throat surface adjacent said relieved portion radially and angularly inwardly against said relieved portion While maintaining all other portions of throat metal against deformation in any direction.

, 2. In the method of forming a rear axle housing of the banjo type having smoothly tapering throat portions between the cylindrical banjo section and the oppositely extending arms, the step of forming a spring pad seat in one of said throat portions which comprises maintaining said throat portion against deformation in any direction except at the portion where said seat is to be formed, and forcing the metal at said lastnamed portion inwardly against a recessed abutment to produce a horizontal spring pad s'eat located radially beyond the diameter of the adjacent arm. l

3. In the method of forming a spring Dad seat in the throat portion of a banjo type axle housing, which includes drawingsaid throat portion with a male mandrel therein into a female die having a laterally shiftable section, the novel steps comprising internally supporting the throat metal against inward deformation except in the portion where said spring pad seat is to be formed, externally supporting the throatI metal against deformation, withdrawing a portion of external support in the portion where said spring pad seat is to be formed, and then forcing throat metal inwardly at said last-named portion to form a horizontal spring pad intermediate the ends of the throat' portion.

4. In the method of making an axle housing having an offset expandedcylindrical banjo portion, the novel steps which comprise rst forming a smoothly tapered throat portion between said banjo portion and the adjacent housing arm by inserting a mandrel in said throat portion and moving the mandrel and housing throat into a female die, then reforming a portion of said throat portion to form a spring pad seat by retaining all other portions thereof against deformation and, forcing metal in said one portion inwardly and laterally to produce a iiatted horizontally extending step in the intermediate surface of said throat portion.

5. In the method of making an axle housing having an expanded cylindrical banjo portion and oppositely extending arms of unequal length, the portions of said housing `between said banjo and said arms comprising smoothly tapering throats merging from the diameter of said banjo to the cross-section of said arms, the novel step of forming a spring pad in the throat between the shorter of said arms and said banjo, which comprises internally supporting the metal in said throat except for a relieved portion where said parallel to the longitudinal axis of said housing.

6. In an axle housing of the type having a transverse cylindrical banjo joined to oppositelyl extending arms by smooth taperingv throats of generally frusto-conical form, the method of forming a spring pad seat in one of said throats intermediate the ends thereof which comprises internally supporting the metal in all portions of said throat against inward movement at the portion where said seat is to be formed, externally supporting the metal of said throat against deformation outwardly, deforrning the throat metal inwardly at said one portion where said seat is to be formed, and providing within said throat a horizontal internal abutment limiting inward movement of said deformed metal to produce a horizontal spring pad seat spaced radially from the longitudinal axis of said housing a distance intermediate the radial extents of the large and small ends of said throat.

WILLIAM JACK STEPHEN EKINS. 

